MATH
posted by NICK .
HARRIET BOUGHT CHRISTMAS CARDS.
SHE BOUGHT 1 BOX WITH 15 CARDS FOR $18.00,
1 BOX WITH 12 CARDS FOR 20.00, AND 2 BOXES WITH 10 CARDS FOR $8.00 EACH.
WHAT WAS THE AVERAGE PRICE SHE PAID PER CARD?

18 + 20 + 16 = $54
15 + 12 + 10 + 10 = 47
54 / 47 = ?